1986 yamaha 175 wont start

[kevin h]

i have a 1986 175 yamaha that at the end of last year i seized the lower unit. after replacing it ,i tried to start the motor and had no spark.tried a few things and decided to call the local mechanic ,who i don't know but has a reputation of being knowledgable in yamahas.he tested and said that there was no spark and after by passing cdi with the "a" and "b" cables i had spark in one cylinder and his diagnosis was that i need a new cdi. this doesn't make sense to me ,any help would be appriciated.and do i have a crank sensor on this motor and could that be the problem .and one more thing where is the best place to get a manuel for this specific motor ,,thanks

[99yam40]

not sure about a motor that old, but the newer ones you need to test the input into the CDI and the outputs of the CDI with the proper test equipment to determine what the problem is.

Look here to find you yamaha service manual # for your motor and then see what a search of the web gives you using that #. Or buy from Yamaha dealer
YAMAHA MANUAL STORE

What did you end up doing on your lower unit with the wrong shaft?

[rodbolt17]

really need a model number.
best I remember the 1986 175 2.6L v6 used 3 pulsers and a CDI unit but did not use the TPS and the ECU setup like the excell models.
means it used a movable timer base without the A and B ECU bypass.
all the A and B bypass did was eliminate the ECU functions and spark timing was fixed and triggered strictly by the pulser coils.
myself, I would carefully test the charge coil and pulser coil inputs to the CDI.
that CDI is rather pricey.
you may wish to find a dealership with a master tech employed or at least one with the electrical training certificate on the wall from yamaha.

[kevin h]

i ended up rebuilding the lower unit ill advised cost a fortune ,basically everything had to be purchased .the guy who did it was very good, but it was one step at a time took 3 months ,everytime he put one part in,another one was no good and had to be ordered .ended up costing about 1800. ,but its now just about new.I am new at this so i'm learning the hard way.when the lower unit seized it locked up in gear ,but would crank, could i have damaged something electronically trying to start the boat ,i was trying to get out of the water ,or is it just a coincidence that this happened right after the lower unit went bad ,thanks

[kevin h]

model number V6 SPCLJ 607-301-412 J the only place i know of near me wants $100.00 an hour and said it could take up to 10 hrs just to diagnos the problem. i did a compression test and was getting at least 120 all around ,i know it's a old motor but i think it's repaiable and has alot of hours left in it .but $1000.00 just to find out what's wrong might be a little much thanks

[99yam40]

I think some one is blowing smoke and they do not want to work on your motor. Is this a Yamaha shop?

I would think that it could be tested in less than an hour, but Rodbolt is the guy with the knowledge as he does that for a living, do what he recommends.

Did you try the link to see if you could find manual?

[rodbolt17]

and now the issue starts.
you may have a 175 hood but from my parts manuals and service manuals its not a 175.
however by the model numbers you do have a V6 special motor thats old as dirt.
now I need pictures, the more the better.
simple system to actually trouble shoot, should take less than 2 hours max.
expensive system to fix.
in parts smart I can find the 85 model sp and the 87 but no 86.
however when you bypass the ECU it leaves either the kill switch,CDI or pulser coil assybly.
also carefully index the flywheel to insure the key wasnt broken when the lower seized and tossed the pulser timing into left field.

[kevin h]

yes i looked at the web site but still not exactly sure which manuel to get ,nothing matches the model number i have ,which i took off the engine bracket ,i will see some folks this weekend at our club work party ,hopefully some one there will tell me if i even have the right model number

[rodbolt17]

V6spclj
V6 2.6L
special
20" shaft and 1986 model designation.
but from what I can find its not a 175.
thats why I would like some pictures.
port side,stbd side and aft with the hood off.
but ya have to remember in 86 I was programming and setting up CNC lathes and mills.
from 87 to 93 I was an an FC in the USN with an NEC of 1127.
did not start back to working with outboards until 95.
in the salt pond most of your model engines had started dissapearing due to corrosion.
but with pictures I can determine which system you have.

[99yam40]

If this happened at the time you locked up the lower unit then take Rods advice and check the flywheel key as that is the only thing that makes since.
and post the pics

[kevin h]

my guess it's an 85.i came up with 86 because of the model number going by the last letter iwas told it was an 86 but the boat (another 1 of a kind "22.5' American International center console, nice boat actually) is a 85 .I got it from my sister ,who got it from her sister in law who got it from her father, who purchased it new and kept it in the same club i am now a member of.Bently Yacht club S.I. N.Y. another !of kind place. Boat has low hours and i enjoyed the hell out of that boat last year when it was running, It is my first boat ,me just turning fifty would like to continue enjoying this ,but new is not in my budget at the present time ,so all help is deeply appriciated .i'll try to get pictures on tomorrow ,how do i do that. thanks

[99yam40]

i believe LIT-18616-V6-NK is the manual #

YAMAHA MANUAL STORE


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[kevin h]

trying to send pics hope it works

[rodbolt17]

definantly a V6 spcl.
with the A&B circuits bypassed the ECU is no longer controling spark.
means spark timing is fixed by pulser coils pyshical psition, about 7* BTDC and will spark IF pulser coil signal AND charge coil inputs to the CDI are good.
test CDI charge coil and pulser coil inputs.
the black cover on the stbd side is the CDI the one aft between the heads is the ECU or micro processor.
under normal conditions the pulser coils signals are fed to the ECU and the ECU triggers the CDI altering ign timing electronically based on various sensor inputs.
when the A&B connectors are connected the pulsers bypass the ECU and now the pulsers feed the CDI unit directly.
always check spark PRODUCING components THEN spark CON*****ING.
in your case spark producing are flywheel,pulsers,stator charge coils and the CDI.
odds of 6 ign coils failing at the same time are slim.
also check the plug cap resistance.

[kevin h]

thank you everyone for your in put ,i ordered the manuel and hopefully will have time this weekend to start (if it doesn't snow again , that's the latest report) i get back to you and let you know how i make out ,thanks again